The great white shark is a streamlined swimmer and a ferocious predator with 3,000 teeth at any one time. This much-feared fish has a torpedo-shaped body, a pointed snout, a crescent-shaped tail, 5 gill slits, no fin spines, an anal fin, and 3 main fins: the dorsal fin (on its back) and 2 pectoral fins (on its sides). When the shark is near the surface, the dorsal fin and part of the tail are visible above the water.
Only the underbelly of the great white shark is actually white; its top surface is gray to blue gray. This is useful in hunting its prey. The great white usually strikes from below and its grayish top coloration blends in with the dark water, enabling it to approach the prey unobserved.
Great whites average 12-16 feet long (3.7-4.9 m) long, weighing about 5,000 pounds (2,268 kg). The biggest great white shark on record was 23 feet (7 m) long, weighing about 7,000 pounds (3200 kg). Females are larger than males, as with most sharks. Shark pups can be over 5 feet (1.5 m) long at birth.
Young great white sharks eat fish, rays, and other sharks. Adults eat larger prey, including pinnipeds (sea lions and seals), small toothed whales (like belugas), otters, and sea turtles. They also eat carrion (dead animals that they have found floating dead in the water). Great whites do not chew their food. Their teeth rip prey into mouth-sized pieces which are swallowed whole. A big meal can satisfy a great white for up to 2 months.
The great white shark has 3,000 teeth at any one time. They are triangular, serrated (saw-edged), razor-sharp, and up to 3 inches (7.5 cm) long. The teeth are located in rows which rotate into use as needed. The first two rows are used in obtaining prey, the other rows rotate into place as they are needed. As teeth are lost, broken, or worn down, they are replaced by new teeth that rotate into place.
Shark's primarily use their sense of smell followed by their sensing of electric charges. The shark's other senses, like sensing changes in water pressure, eyesight, and hearing, are less important. The great white's nostrils can smell one drop of blood in 25 gallons (100 liters) of water. (Shark nostrils are only used for smell and not for breathing, like our nostrils. They breathe using gills, not nostrils.) The sensing of minute electrical discharges in the water is accomplished by a series of jelly-filled canals in the head called the ampullae of Lorenzini. This allows the shark to sense the tiny electrical fields generated by all animals, for example, from muscle contractions. It may also serve to detect magnetic fields which some sharks may use in navigation. The great white is the only type of shark that will go to the surface and poke its head up out of the water. No one knows exactly why it does this; perhaps it is to see potential prey such as surface-dwelling sea lions.